What can cause a dry cough?
A dry cough, or sometimes a tickly cough, is a cough that does not bring up any phlegm or mucus. Dry coughs may cause a tickling sensation and are often due to irritation in the throat.
Doctors often refer to dry coughs as non-productive coughs. In contrast, a wet, or productive, cough brings up phlegm that helps clear the airways of irritants.
Doctors also classify coughs as either acute or chronic. A cough is chronic if it lasts longer than 8 weeks.
In this article, we describe some of the possible causes of a dry cough and the treatment options. We also discuss diagnosis, general treatments, prevention tips, and when to see a doctor.
Symptoms of asthma can include wheezing and shortness of breath.
Asthma is a long-term lung condition that leads to inflammation and narrowing of the airways in the lungs. One of the most common symptoms of asthma is coughing, which is often worse at night or early in the morning when a person first wakes up.
The cough is often productive, meaning it brings up phlegm. However, in a type of asthma called cough-variant asthma, the main symptom people experience is a dry cough.
Other symptoms of asthma can include:
- shortness of breath
- chest tightness or pain
There is currently no cure for asthma, so treatment focusses on relieving symptoms and preventing future attacks.
Typically, doctors prescribe the following treatments for people with asthma:
- a quick-relief inhaler, such as a short-acting beta-2-agonist, for treating symptoms when they flare-up
- long-term medications, such as a low-dose corticosteroid inhaler, for reducing inflammation and preventing future attacks
Idiopathic pulmonary fibrosis
Idiopathic pulmonary fibrosis (IPF) is a condition in which scar tissue develops inside a person's lungs. As the scar tissue thickens, it makes breathing in air increasingly difficult. The term idiopathic means that doctors do not know exactly what causes the condition.
One of the most common symptoms of IPF is a persistent, dry cough. Other symptoms can include:
- shortness of breath
- loss of appetite and gradual weight loss
- clubbing, or widening and rounding of the tips of the fingers or toes, also affecting the shape of the nails
There is currently no cure for IPF, so the aim of treatment is to relieve a person's symptoms and slow disease progression.
Treatment options for IPF include:
- medications such as pirfenidone and nintedanib
- oxygen therapy
- pulmonary rehabilitation, which is a program of exercises, training, and support for people with long-term lung conditions
- lung transplantation
Gastroesophageal reflux disease
Gastroesophageal reflux disease (GERD) is a condition where acid leaks from the stomach back up into the esophagus, or food pipe.
According to a 2015 review, GERD causes a chronic, dry cough in up to 40 percent of people with the condition.
GERD typically also causes a number of gastrointestinal symptoms, which may include:
However, research suggests that up 75 percent of people with GERD-related cough may not experience these gastrointestinal symptoms. This can make it difficult for doctors to diagnose GERD in people with just a chronic, dry cough.
Many people can manage symptoms of GERD through lifestyle changes, such as:
- eating multiple small meals each day instead three large meals
- limiting or avoiding foods that trigger or worsen symptoms, such as fatty or spicy foods
- maintaining a healthful weight
- quitting tobacco smoking
- reducing or avoiding alcohol intake
Over-the-counter (OTC) and prescription medicines, such as antacids, H2-recepter blockers, and proton pump inhibitors may also help relieve or prevent symptoms.
Symptoms of postnasal drip can include a feeling of something in the back of the throat.
Postnasal drip is when mucus from the nose and sinuses drips down the back of the throat.
When the mucus drips into the throat, it can trigger a cough. Although this cough is often productive, it can sometimes also be dry.
Postnasal drip often occurs with a sinus infection or due to a nasal allergy, such as hay fever.
Other symptoms of postnasal drip may include:
- runny nose
- a feeling of something in the back of the throat
- sore throat
- frequent swallowing
Treatment options for postnasal drip includes decongestants, nasal sprays, and nasal saline irrigation.
Upper respiratory infections
Upper respiratory infections such as common colds and the flu can cause acute coughing. The cough often starts out productive but may become dry as a person recovers from the infections.
Other symptoms of upper respiratory infections may include:
- muscle aches
- runny nose
- sore throat
A person can usually treat viral upper respiratory infections at home with plenty of rest, staying properly hydrated, and taking OTC medications to relieve aches and fever. A doctor may prescribe an antiviral medication for people with the flu.
A chronic, dry cough can sometimes be a symptom of lung cancer. However, other causes of dry cough are far more common.
Symptoms of lung cancer can include:
- coughing up blood or phlegm that contains blood
- chest pain that may get worse with breathing or coughing
- weight loss
- shortness of breath
- feeling weak
Treatment depends on the type and stage of the lung cancer. Early diagnosis and treatment can significantly improve a person's outlook
Other causes of a dry cough can include:
- cigarette smoking
- prolonged exposure to pollution, dust, and irritating chemicals
- some medications, such as ACE-inhibitor drugs for high blood pressure
A doctor may order a CT scan to diagnose the cause of a dry cough.
To diagnose the cause of a dry cough, a doctor will usually begin asking about a person's symptoms and their medical history. They will then perform a physical examination.
A doctor may also need to order some tests to help with their diagnosis. These may include:
- Imaging tests. An X-ray or CT scan creates an image of the inside of the chest that allows doctors to check for problems.
- Spirometry. This involves breathing into a plastic device to check a person's lung functioning. Doctors use spirometry to help diagnose conditions such as asthma or IPF.
- Endoscopy. An endoscope is a long, thin tube with a camera and light on the end. With upper gastrointestinal endoscopy, doctors can insert the tube through a person's mouth and down the throat to check for problems inside the esophagus, stomach, and beginning of the small intestine. For bronchoscopy, the tube is inserted through the mouth, but doctors look at the windpipe and airways.
Treating the underlying cause is usually the best way to reduce severity and frequency of a dry cough. However, general treatments that may improve a person's symptoms include:
- Sucking on throat lozenges. Throat lozenges contain ingredients such as honey, menthol, and eucalyptus, which may ease irritation and reduce coughing.
- Taking cough suppressants. OTC cough suppressants, which often contain dextromethorphan, may reduce a person's cough reflex.
- Elevating the bed. Sleeping with the upper body elevated by 6 to 8 inches can help decrease symptoms of postnasal drip and GERD. A person can elevate the bed by placing blocks or wedges under the bed posts.
- Taking a hot shower. The warm water and steam from the shower may ease throat dryness and irritation.
It is not always possible to prevent a dry cough. However, tips that can help include:
- avoiding tobacco smoke
- drinking plenty of water
- using a humidifier to moisten the air
- allergy-proofing the bedroom to reduce irritants
When to see a doctor
People with dry coughs that get worse, do not go away, or cause one to start producing blood or green mucus should see a doctor.
It is also advisable for a person to see a doctor if a dry cough occurs along with any of the following symptoms:
- a feeling of something being stuck in the throat
- shortness of breath or difficulty breathing
- trouble swallowing
A dry cough is one that does not produce phlegm or mucus. Dry coughs are often temporary and rarely a cause for concern. However, a chronic, dry cough may be a symptom of an underlying condition, such as asthma or GERD.
Treating the underlying cause is the best way of reducing the severity and frequency of chronic coughs, but OTC remedies may also help relieve symptoms.
People should see a doctor for dry coughs that do not get better or start bringing up blood.